1. Field
Embodiments of the present invention generally relate to rapid thermal processing (RTP) chambers, and more particularly, to vacuum RTP chambers having an internal rotation device.
2. Description of the Related Art
RTP system technologies have been developed to increase manufacturing throughput of substrates while minimize their handling. The types of substrates referred to here include those for ultra-large scale integrated (ULSI) circuits. RTP refers to several different processes, including rapid thermal annealing (RTA), rapid thermal cleaning (RTC), rapid thermal chemical vapor deposition (RTCVD), rapid thermal oxidation (RTO), and rapid thermal nitridation (RTN).
The uniformity of the process over the surface of the substrate during thermal processing is also critical to producing uniform devices. For example, in the particular application of complementary metal-oxide-semiconductor (CMOS) gate dielectric formation by RTO or RTN, thickness, growth temperature, and uniformity of the gate dielectrics are critical parameters that influence the overall device performance and fabrication yield. Therefore, techniques that minimize temperature non-uniformity are very important.
One way of achieving temperature uniformity is by rotating the substrate during processing. This removes the temperature dependence along the azimuthal degree-of-freedom. Conventionally a magnetically-levitated rotor system has been utilized to rotate the substrate. However, the costs become prohibitive at the larger substrate sizes along with the issues of electrical noise immunity and magnetic coupling deficiency.
Therefore, an improved rotation device is needed in an RTP chamber.